/Engine/Plugins/Runtime/RigVM/Source/RigVMDeveloper/Public/RigVMCompiler/RigVMAST.h
An abstract syntax tree var expression represents the definition of mutable memory for a single variable. In C++ the var expression is a variable declaration: int A; The var expression references a pin from the model.
class FRigVMVarExprAST : public [FRigVMExprAST](API\Plugins\RigVMDeveloper\RigVMCompiler\FRigVMExprAST)